Fallen Exorcists?

greetings all, as the title suggests, I’m wondering if there have been any recorded cases, or at least mentions, of possible traitor and or fallen Exorcist marines? I’m aware it would be EXTREMELY rare even if they have, I just had an idea as I’m working on a word bearers warband and was wondering if it would have ever been possible for an Exorcist to fall.

any assistance is much appreciated, and have a great day